What Can Evolution Do?

Malaria is the million person Murderer; it kills 1 million people each year, and makes 100 million other people sick. In some regions, it kills half of all children before the reach the age of 5. It is like Dracula, feeding on blood. It is carried by mosquitoes, and transmitted when they bite. Once inside a person they keep feeding until they reach the liver, where they stop to multiply. It attaches to a red blood cell, goes inside puts a protective covering on and feeds on the hemoglobin. The infected blood cell gets stuck in our veins and stops circulating. Malaria reproduces until about 20 copies are made, they then break out of the now trashed red blood cell and re-enter the bloodstream to go into more red blood cells. They multiply exponentially, so that within a few days there are a trillion new malarial parasites, which consume a large portion of the victim’s blood. Because they are so numerous, and it has been studied so much, it is the best example of what evolution can do.

The modern fight against malaria began in South America with the discovery that bark from the cinchona tree was useful for treating the fever. Quinine is developed from the cinchona bark, and once it was discovered in the 17th century that it could be used as a cure for malaria. But in the 1940’s the active ingredient was isolated, and a compound developed called ‘Chloroquine’ that was even more effective against malaria. Because Chloroquine was effective, with few side effects and inexpensive to make it became the drug of choice for treatment of malaria for decades.

Malaria has 14 chromosomes, and the resistance part was recently discovered to be part of a 400,000 nucleotide region of one chromosome. It was further narrowed to 36,000 nucleotide region. The complexity of even a simple parasite like malaria is mind-blowing. The DNA for malaria encodes 5,300 proteins (proteins are essential to the operation of the cell, participating in every process of the cell. This includes being enzymes for metabolism, structural and mechanical functions – like forming the cell structure and building muscles, cell-signaling, immune responses and cell adhesion.) The PfCRT protein (for P. falciparum, a malaria species - Throughout my post when I use ‘malaria’, it is for P. falciparum) normally has 424 amino acids in a strict sequence. When there is a change in the amino acid sequence, the change commonly happens at position number 76 and 220. These mutations are what have provided malaria’s resistance to Chloroquine. This is what evolution can do in making an organism more resistant to an enemy like Chloroquine that is designed to destroy malaria.
So these two mutations at spot 76 and 220 of the amino acid sequence are what Darwinism can do – they provide resistance to the primary drug used to fight malaria; Chloroquine. Remember, that there are 1 trillion malaria cells in an infected person. And there are over 500 million people infected each year. Tom’s Important Point: So with so many malaria cells (1 trillion in a sick person) and so many people infected with malaria (500 million each year), how often does a simple double mutation of the amino acid sequence happen to provide resistance to the top drug used to fight Chloroquine? One researcher has estimated that it has only happened 10 times over the past 50 years.

Resistance to Chloroquine has only appeared 10 times in the whole world in the past 50 years (!!!). And so, one writer estimates that if you count the number of malaria cells in a very sick person times the number of people who get malaria each year times the number of years since Chloroquine was introduced, we see that the odds of a parasite developing resistance to Chloroquine is roughly one in a hundred billion billion. Written in shorthand this is 1 in 10²⁰. Most of the information in this post is from Prof. Michael Behe’s recent book: The Edge of Evolution. My background is not in science, and so if you find anything that needs to be corrected, please be gentle. Your first course in molecular biology is now concluded.